Electric fire-alarm system.



J. L. PLAGG & F. T. TOWERS. ELECTRIC FIRE ALARM SYSTEM. APPLICATION FILED JUNE '1, 191a.

1,975,31Q, Patented 0013.7, 1913.

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UNTTEE STATES PATENT OFETQE.

JOHN L. FLAGG, OF HACKENSAGK, AND FORD T. TOWERS, OF HAWTHORNE, NEW JERSEY, ASSIGNORS TO WATSON-ELECTRIC (30., OF PATERSON, NEW JERSEY,

A CORPORATION OF NEW JERSEY.

ELECTRIC FIRE-ALARM SYSTEM.

Specification of Letters Batent.

Patented Oct. '7, 1913.

Application filed June 7, 1913. Serial No. 772,275.

To all whom it may concern Be it known that we, JOHN L. FLAoo, a citizen of the United States, and a resident of Hackensack, county of Bergen, and State of New Jersey, and FORD T. Townes, a citizen of the United States, and a resident of Hawthorne, county of Passaic, State of New Jersey, have invented certain new and useful Improvements in Electric Fire-Alarm Systems, of which the following is a specification, reference being had to the accompanying drawing, forming a part thereof.

Our invention relates to electric signal systems and particularly to such as are adapted to be installed in factories and other buildings for controlling fire alarm signals.

One object of our invention is to provide a system of the aforesaid class, that shall be relatively simple in arrangement and reliable in operation.

Another object is to provide a system, which is adapted to utilize an ordinary available source of electric energy such as a service line and which at the same time, embodies an alternative source of supply, such for example as a storage battery.

A further object is to provide, in a fire alarm signal system, an automatic changeover switch, for automatically changing the connections of the system from the service line to the storage battery or vice versa, dependent upon the failure or restoration of voltage on the service line.

Other objects will be set forth hereinafter.

We will describe our invention in the following specification and point out the novel features thereof in appended claims.

The single figure of the accompanying drawing is a diagrammatic view of a system arranged in accordance with and embodying our invention.

Referring to the drawing,10 represents a suitable source of electric energy such for example as a direct current generator. This is intended to be illustrative of any available source of electric energy in the mill or factory, in which the system is to be employed. The current from this source is conveniently referred to as the available mill current. A storage battery 15 forms a part of the same system and is adapted to supply energy thereto whenever the generator 10 is shut down or its circuit interrupted for any cause.

Connected in circuit between the sources 10 and 15 is a change-over switch 20 which is adapted to occupy an up position X or a down position Y depending upon the energization or deenergization of an actuating magnet coil 21. The system further comprises alarm circuits, A and B and a signal circuit C.

In each of the alarm circuits are audible or visual alarm devices which are connected in multiple circuit relation. We prefer to utilize m otor operated horns such as are in general iis'fiTtiiFdfibbil'e'fiiid consequently we will refer to the alarm circuits A and B as horn circuits. These circuits are respectively provided with switches 25 and 30 which are normally held open by weights 26 and 31 or other suitable means and are only closed when magnet windings 27 and 32 are energized.

The signal circuit C includes a resistance 50, a milli-ammeter 4.5, magnet coils 61, 63 and 65 of relay switches 60, 62 and Get, and a plurality of signal boxes or stations 40 40, 40 40, 40 and 40 all of which are connected in series circuit relation. The relay switches 60 and 62 are normally open and are arranged to govern the energization of the respective switch magnet windings 27 and 32. The relay switch 64 is also normally open and is arranged to govern a trouble bell 70 which is connected in an open circuit with an auxiliary source of energy such as a primary battery 71. The energization of switch magnet windings 27 and 32 also depends upon relay switches 75 and 77 having volt-age coils 7 6 and 78 which are connected across the respective horn circuits, the design of the coils and the circuit arrangement being such that the relay switches 75. and 7 7 are only open when the horn circuit voltages exceed predetermined values. The magnet winding 21 of the change-over switch is connected directly across the available mill current circuit and consequently is energized except when this current fails or is cut off for any cause. This coil when energized, throws the changeover switch to its position X.

The operation of the system and its circuit connections are as follows: Assuming that the generator 10 is in operation so that the magnet Winding 21 is energized and the change-over switch 20 in its position X, the signal circuit is completed from the positive terminal 11 of the generator through a conductor 12, bridged contacts 13 of the changeover switch, conductor 14, resistance 50, milli-amineter 45, conductor 16, magnet coils 61, 63 and 65 of the relay switches 60, 62, and 64, conductor 17, signal boxes or stations 40, 40, 40 etc., conductor 18, a resistance 19, conductor 23, bridged contacts 24 of the change-over switch, and conductor 28 to the opposite terminal 29 of the generator. The positive terminal of the storage battery 15 is also connected to the conductor 14 and its negative terminal is connected to the conductor 18 so that the signal circuit C is supplied with energy from one or both of the two sources 10 and 15 at all times. The resistance 50 determines the current which traverses the signal circuit while resistance 19 is intended to compensate for the difference in voltage between the battery and the source of available mill current. The amount of energy expended continuously in the signal circuit C is very slight as this is a relatively high resistance circuit, and the amount of this current is always indicated by the meter 45.

All of the signal boxes or stations are arranged in series in order that the circuit may be interrupted at any one of them in a well known manner.

The structure of each signal box is immaterial to our invention and as devices of this character are very well known, we will not describe any of them in detail. Each box is arranged to interrupt the signal circuit so as toproduce a predetermined signal when the hand lever in the box is actuated. The interruptions are temporary in every case and the intervals between the interruptions and the number of such interruptions determine the signal.

If the current traversing the signal circuit should fall below a predetermined value, this abnormal condition will immediately be called to the attention of some attendant by reason of the fact that the relay switch 64 will fall and will complete a circuit from the primary battery 71 through the trouble bell 70. This device is intended to operate if both of the sources 10 and 15 become inactive so that the interruption of the signal circuit would fail to produce any operation of the alarm devices.

The switches 25 and 30 keep the horn circuits A and B open except when the signal circuit C is interrupted. An interruption of the signal circuit is instantly followed by a deenergization of the coils 61 and 63 and a closing of the relay switches 60 and 62. When these switches are closed, the change-over switch being in position X, as above assumed, the horn control circuits are completed through the conductor 12, through contacts 13, a conductor 14, a horn resistance 36, conductor 37, the circuit being continued in two branches, one through relay switch 60, conductor 38, over voltage relay 75, conductor 39, magnet coil 27 of switch 25, conductor 41, horn resistance 42, conductor 23, contacts 24 and conductor 28 to the opposite generator terminal. The other branch is completed from conductor 37, through relay switch 62, conductor 43, over voltage relay 77, conductor 44, and coil 32 of switch 30, to the conductor 41, circuit being completed from this point as before. The magnet coils 27 and 32, when energized, close the switches 25 and 30 and conse quently establish the two horn circuits A and B. All of the horns or other alarm devices may of course be connected to a single circuit, or three or more circuits may be employed as desired.

Assuming that the generator 10 is shut clown, as is frequently the case in a factory provided with an independent generating plant, the coil 21 will be deenergized and the change-over switch will immediately move to position Y. Conductors 37 and 41 of the horn control circuits are then connected through bridged contacts 51 and 52 of the change-over switch and conductors 53 and 54 to the respective terminals of the battery 15, the resistances 36 and 42 then being excluded. The whole system now de pends upon battery 15 with the single exception of the trouble bell circuit which is supplied from the primary battery 71. It is thus evident that the change-over switch 20 automatically connects the system to the available mill current source as long as this source is active, and automatically connects the system to the storage battery whenever voltage fails on the mill current source with out interrupting the signal circuit or energizing the horn control circuits.

hen the available mill current source is active and the change-over switch occupies its position X, the storage battery 15 and the generator 10 are connected in multiple circuit relation to the signal circuit. Consequently each source supplies a proportion of the 'current consumed in the signal circuit dependent upon voltage of each source and the resistances 19 and 50, both resistances being included with the generator and only resistance 50 being included in circuit with the battery.

The resistances 19 and 50 may be so proportioned that the generator which represents the available mill current source of energy will supply a greater proportion of the current consumed in the signal circuit lt han the battery in order to favor the battery as far as possible. Care must be taken however to keep the generator and battery voltages sufficiently balanced to prevent a continual charging of the battery.

Attention may be directed to some of the advantages incident to the use of this system as follows: The system embodies a storage battery so that it is independent of the failure of any other source. The signal circuit which requires only a small amount of energy is positively connected to the storage battery which is assisted by the other available source whenever the latter is active. It is therefore never interrupted, except at the signal boxes or stations and consequently the change-over switch may operate to connect the system from one source to the other without producing an alarm. Second, at the same time the battery is not frequently called upon to deliver energy to the alarm circuits of the system and consequently only requires infrequent charging. l urthermore its life is materially prolonged. Third, the horn circuits are protected against over voltage by the relay switches and 77. Fourth, the switches 25 and 30 which are normally open and are closed in opposition to weights or sp 'ings or the like, may readily be designed and constructed to interrupt the horn circuit which may be traversed by relatively large currents. The closing magnet coils of these switches may be made rela tively powerful without an excessive number of turns since they are only temporarily energized and are connected in normally open circuits governed by relay switches.

Other advantages of our system will be apparent to those skilled in the art.

Any independent source of electrical supply, such for example as a street service line, may be used instead of the storage battery.

The arrangement and form of switches and other devices of which the system is composed may be materially varied within the spirit and scope of our invention and the circuit connections may be rearranged without materially changing the results effected. e therefore intend that only such limitations be imposed as are indicated in the appended claims.

lVhat we claim is:

1. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit, permanently connected to the alternate source, of a normally open alarm circuit, means for connecting the alarm circuit to one or the other of said sources of energy and means dependent upon the interruption of the signal circuit for closing the alarm circuit.

2. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit, permanently connected to the alternate source, of a normally open alarm circuit, means for connecting the alarm circuit to one or the other of said sources of energy, means dependent upon the interruption of the signal circuit for closing the alarm circuit and a Voltage equalizing resistance adapted to be interposed between said sources of energy.

3. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit permanently connected to the alternate source, a plurality of signal boxes or stations in said circuit, each of which is adapted to temporarily interrupt the circuit, of a normally open alarm circuit, a plurality of alarm devices in multiple circuit relation therein, a normally open switch in the alarm circuit, means for connecting the alarm circuit to one or the other of said sources of energy and means dependent upon the interruption of the signal circuit for actuating said switch to close the alarm circuit.

4. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit permanently connected to the alternate source, a plurality of signal boxes or stations in said circuit, each of which is adapted to temporarily interrupt the circuit, of a normally open alarm circuit, a plurality of alarm devices in multiple circuit relation therein, a normally open switch in the alarm circuit, a change-over switch for connecting the alarm circuit to one or the other of said sources of energy, means dependent upon the energization of said preferred source of energy for actuating the change-over switch to connect the alarm circuit to the preferred source, and means dependent upon the interruption of the signal circuit for closing the alarm circuit.

5. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit permanently connected to the alternate source, a plurality of signal boxes or stat-ions in said circuit, each of which is adapted to temporarily interrupt the circuit, of a normally open alarm circuit, a plurality of alarm devices in multiple circuit relation therein, a normally open switch in the alarm circuit, a change-over switch for connecting the alarm circuit to one or the other of said sources of energy, a magnet. coil for holding the change-over switch in a position to connect the alarm circuit to the preferred source of energy, an electroanagnet for closing said. normally open switch to complete the'alarm circuit and a relay switch dependent upon an interruption of the signal circuit for energizing the closing coil of the normally open switch and completing the alarm circuit, the

f electro-magnet associated with the change over switch being connected across the preferred source of energy.

6. In an alarm signal system, the combination with an available mill current source of energy, a storage battery, a normally closed high resistance circuit, permanently connected to the storage battery, a plurality of signal boxes in said high resistance circuit, each of which is adapted to temporarily in terrupt the circuit, of a normally open alarm circuit, electro-responsive alarm devices connected in multiple circuit relation therein, a change-over switch having a magnet coil connected across the available mill current source for throwing the switch to such a a position as to connect the alarm circuit to said available mill current source, an electro-responsive switch in the alarm circuit and a relay switch for controlling the electro-responsive switch dependent upon the interruption of the high resistance circuit, said change-over switch being adapted, when its coil is deencrgized, to connect the alarm circuit to the storage battery and said electro-responsive switch being arranged to occupy its open position when its coil is deenergized.

7. In an alarm signal system, the coinbination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit permanently connected to the alternate source, a plurality of signal boxes or stations in said circuit, each of which is adapted to temporarily interrupt the circuit, of a normally open alarm circuit, a plurality of alarm devices in multiple circuit relation therein, a normally open switch in the alarm circuit, means for connecting the alarm circuit to one or the other of said sources of energy, means dependent upon the interruption of the signal circuit for actuating said switch to close the alarm circuit and a voltage equalizing resistance between said sources of energy.

8. In an alarm signal system, the combination with an available mill current source of energy, a storage battery, a normally closed high resistance circuit, permanently connected to the storage battery, a plurality of signal boxes in said high resistance circuit, each of which is adapted to temporarily interrupt the circuit, of a normally open alarm circuit, electro-responsive alarm devices connected in multiple circuit relation therein, a change-over switch having a magnet coil connected across the available mill current source for throwing the switch to such a position as to connect the alarm circuit to said available mill current source, an electro-responsive switch in the alarm circuit, a relay switch for controlling the electroresponsive switch dependent upon the interruption of the high resistance circuit, said change-over switch being adapted,

when its coil is denergized, to connect the alarm circuit to the storage battery and said electro-responsive switch being arranged to occupy its open position when its coil is deenergized, and a voltage equalizing resistance between said sources of energy.

9. In an alarm signal system, the combination with an available mill current source of energy, a storage battery, a normally closed high resistance circuit, permanently connected to the storage battery, a plurality of signal boxes in said high resistance circuit, each of which is adapted to temporarily interrupt the circuit, of a normally open alarm circuit, electro-responsive alarm devices connected in multiple circuit relation therein, a change-over switch having a magnet coil connected across the available mill current source for throwing the switch to such a position as to connect the alarm circuit to said available mill current source, an electro-responsive switch in the alarm circuit, a relay switch for controlling the electro-responsive switch dependent upon the interruption of the high resistance circuit, said change-over switch being adapted, when its coil is deenergized, to connect the alarm circuit to the storage battery and said electro-responsive switch being arranged to occupy its open position when its coil is deenergized, a trouble signal a third source of energy adapted to be connected thereto and a control switch dependent upon the failure of current in the signal circuit for energizing the trouble signal.

10. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, a normally closed signal circuit, permanently connected to the alternate source, of a normally open alarm circuit, means for connecting the alarm circuit to one or the other of said sources of energy, a primary battery, a trouble signal connected thereto and means dependent upon the interruption of the signal circuit for closing the alarm circuit and the trouble circuit.

11. In an alarm signal system, the combination with a preferred source of energy, an alternate source of energy, and a normally closed signal circuit permanently connected to the alternate source, of a normally open alarm circuit, means for connecting bot-h the signal circuit and the alarm circuit to the preferred source of energy when said source is active, and for connecting the alarm circuit to the alternate source of energy when the preferred source is inactive, whereby the alternate source always supplies energy to the signal circuit but is assisted by the preferred source whenever the latter is active.

12. In an alarm signal system, the combination with an available mill current source Lof energy, a storage battery, and a normally closed signal circuit permanently connected to the storage battery, of a normally open alarm circuit, a change-over switch for connecting both the signal circuit and the alarm circuit to the available mill current source of energy when said source is active, and for connecting the alarm circuit to the storage battery when the available mill current source is inactive, whereby the battery always supplies energy to the signal circuit but is assisted by the available mill current source whenever the latter is active.

13. In an alarm signal system, the combination with an available mill current source of energy, a storage battery, and a normally closed signal circuit permanently connected to the storage battery, of a normally open JOHN L. FLAGG. FORD T. TOWVERS. Witnesses:

R. J DEARBORN, G. R. QUIMBY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

